The present invention generally relates to composite bonding and curing tools, i.e., bond jigs, and, more particularly, to the assembly of egg-crate substructures for the assembly of bond jigs.
The fabrication of large vehicle components, such as wings for aircraft, often involves the manufacture of composite bonding and curing tools (bond jigs) that comprise a large mold for the component being fabricated. This mold, which is typically of an irregular, non-planar shape, may be supported by a lattice-like base such that the weight of the mold is distributed somewhat evenly about its bottom-facing surface, so as to avoid breaking or damage. The supporting base is referred to as an egg-crate substructure that supports the working surface (facing sheet) of bond jigs.
The egg-crate substructure often consists of a series of intersecting panels, or boards, that are bonded to the backside of the facing sheet. The boards are generally arranged in an egg-crate-like fashion such that the bottom, or floor side, of the egg-crate substructure is flat or planar for setting on a handling cart, or an oven or autoclave rack. A flat bottom of the egg-crate substructure allows for convenient assembly of the egg-crate substructure. The top, or bond jig-facing side, of the egg-crate substructure mirrors the irregular shape of the bond jig and therefore may comprise an undulating, concave, or convex shape such that the bond jig fits securely with the egg-crate substructure.
The attachment of the boards to one another can be accomplished by manually applying strips of fabric wetted with epoxy, referred to as wet-wrapping. This approach basically involves gluing the boards together at its junctures. The wet-wrapping method, however, is labor intensive and requires a lengthy curing period before further work can be performed on the substructure. Labor affects manufacturing costs and the curing period affects fabrication time. Further, the wet-wrapping method involves the use of volatile materials that can be untidy and require certain procedures for removal and disposal.
As can be seen, there is a need for an improved system and method for joining boards for an egg-create substructure for supporting bong jigs. Moreover, there is a need for a more efficient system and method for joining non-orthogonal boards for an egg-create substructure for supporting bong jigs.